Hermetic type compressor with suction pressure adjusting device

ABSTRACT

A hermetic type compressor that includes a sealed casing, a suction pipe, a suction muffler, a compression unit, a driving unit, and a pressure adjusting unit. The suction pipe penetrates a side of the sealed casing. The suction muffler, the compression unit, and the driving unit are within the sealed casing. The suction muffler is coupled to the suction pipe, and the compression unit is coupled to suction muffler. The driving unit is coupled to the compression unit. The pressure adjusting device is on the suction muffler and configured to discharge liquid refrigerant into the sealed casing. The pressure adjusting device maintains the internal pressure of the suction muffler substantially constant.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No. 2006-114792, filed on Nov. 20, 2006, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a hermetic type compressor. In particular, the present invention relates to a hermetic type compressor with an improved suction muffler to restrict liquid refrigerant from being suctioned into a compression chamber. By restricting liquid refrigerant, a compression unit that compresses the refrigerant and a driving unit that provides a driving force to the compression unit are not overloaded.

BACKGROUND OF THE INVENTION

Generally, a hermetic type compressor is employed in a refrigeration cycle of a refrigerator, an air conditioner, and other similar devices. The refrigeration cycle includes a refrigerant, a compressor, a condenser, an expansion device, and an evaporator. The compressor compresses the refrigerant into a high temperature and high pressure gaseous state. The condenser condenses the gaseous refrigerant transmitted from the compressor into a liquid state. The liquid refrigerant then undergoes a throttling expansion in the expansion device and thereby becomes a low temperature and low pressure liquid refrigerant. The evaporator evaporates the low-temperature-low-pressure liquid refrigerant into a low pressure and low temperature gaseous refrigerant. The gaseous refrigerant is then provided to the compressor. As the refrigerant circulates in the refrigeration cycle, it provides cooling by absorbing heat when it evaporates and emits heat when it condenses.

The compressor can be a hermetic type compressor which compresses the low-temperature-low-pressure gaseous refrigerant transmitted from the evaporator of the refrigeration cycle and provides high-temperature-high-pressure gaseous refrigerant to the condenser. Typically, before the hermetic type compressor is started or restarted after being stopped for a predetermined time, a high-pressure side and a low-pressure side of the refrigeration cycle are in equilibrium. When the high-pressure side and the low-pressure side are in equilibrium, an increased amount of the liquid refrigerant enters the hermetic type compressor. When an excessive quantity of the liquid refrigerant is suctioned into and compressed in the compression chamber together with the gaseous refrigerant, compression efficiency of the hermetic type compressor drops, and the refrigerating efficiency of the refrigeration cycle deteriorates.

Moreover, when a larger amount of the liquid refrigerant is transmitted into the suction muffler, the load applied to the compression unit to suction the refrigerant liquid increases, thereby increasing the load on the driving unit to drive the compression unit. The increased load on the compression unit and the driving unit increases the noise of the hermetic type compressor and increases power loss. Thus, in the conventional hermetic type compressor, because the suction muffler guides a great deal of the liquid refrigerant to the refrigerant suction chamber together with the gaseous refrigerant, when the compressor is initially started or restarted, the compression efficiency of the refrigerant deteriorates, noise increases, and excess power is consumed.

SUMMARY OF THE INVENTION

Accordingly, an aspect of the invention is to provide a hermetic type compressor in which a suction muffler substantially prevents liquid refrigerant from being suctioned into a compression chamber and prevents overloading of a compression unit to compress the refrigerant and a driving unit to provide a driving force to the compression unit.

One embodiment of the present invention provides a hermetic type compressor. The hermetic type compressor includes a sealed casing, a suction pipe, a suction muffler, a compression unit, a driving unit, and a pressure adjusting unit. The suction pipe penetrates a side of the sealed casing. The suction muffler, the compression unit, and the driving unit are within the sealed casing. The suction muffler is coupled to the suction pipe, and the compression unit is coupled to suction muffler. The driving unit is coupled to the compression unit. The pressure adjusting device is provided on the suction muffler and configured to discharge liquid refrigerant into the sealed casing. The pressure adjusting device maintains the internal pressure of the suction muffler substantially constant.

Another embodiment of the present invention provides a pressure adjusting device for a suction muffler of a compression unit. The pressure adjusting device includes an opening formed at a side of the suction muffler, an opening and closing member, and an elastic member. The opening and closing member is coupled to the side of the suction muffler substantially adjacent to the opening to open and close the opening. The elastic member has one end to the side of the suction muffler and another end coupled to the opening and closing member biasing the opening and closing member towards the opening. The opening and closing member opens when an internal pressure of the suction muffler increases above a predetermined value.

Yet another embodiment of the present invention provides a pressure adjusting device for a suction muffler of a compression unit. The pressure adjusting device includes an opening formed at a side of the suction muffler, an opening and closing member, a penetrating hole, a corresponding penetration, a hinge shaft, and a torsion spring. The opening and closing member is pivotably coupled to the side of the suction muffler substantially adjacent to the opening to open and close the opening. The opening and closing member is formed with a cut-out part. The penetrating hole is disposed on the opening and closing member. The corresponding penetration is disposed substantially adjacent to the opening. The hinge shaft is disposed in the penetrating hole and the corresponding penetration. The torsion spring is disposed on the hinge shaft with an end coupled to the side of the suction muffler and another end coupled to the opening and closing member biasing the opening and closing member towards the opening. The opening and closing member opens when an internal pressure of the suction muffler increases above a predetermined value.

Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings in which:

FIG. 1 is a sectional view of a hermetic type compressor according to an embodiment of the present invention;

FIG. 2 is a perspective view of a suction muffler of the hermetic type compressor illustrated in FIG. 1;

FIG. 3 is an exploded perspective of a pressure adjusting device of the suction muffler illustrated in FIG. 2;

FIG. 4 is a sectional view of the suction muffler illustrating the operation of the pressure adjusting device when an opening and closing member of the pressure adjusting device is open; and

FIG. 5 is a sectional view of the suction muffler illustrating the operation of the pressure adjusting device when the opening and closing member is closed.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1, a hermetic type compressor according to an embodiment of the present invention is shown. The hermetic type compressor includes a sealed casing 1 to form an exterior, a suction pipe 2 installed on a side of the sealed casing 1 to guide refrigerant from an evaporator of a refrigeration cycle into the sealed casing 1, and a discharge pipe 3 installed on the opposite side of the sealed casing 1 to guide the refrigerant compressed in the sealed casing 1 into a condenser of the refrigeration cycle.

In the sealed casing 1, a compression unit 10 and a driving unit 20 are installed on a frame 30. The compression unit 10 is disposed substantially adjacent to a side of the frame 30, and the driving unit 20 is disposed substantially adjacent to an opposite side of the frame 30. The compression unit 10 compresses the refrigerant, and the driving unit 20 supplies a driving force for the compression of the refrigerant. A shaft 40 is preferably rotatably installed in a substantially central area of the frame 30 and transmits the driving force of the driving unit 20 to the compression unit 10.

In the embodiment shown, the driving unit 20 is disposed on an upper side of the frame 30, and the compression unit 10 is disposed on a lower side of the frame 30. Also, an upper portion of the shaft 40 extends into the upper side of the frame 30, and a lower portion of the shaft 40 extends into the lower side of the frame 30.

The driving unit 20 includes a stator 21 fixed to one side of the frame 30 and a rotor 22 installed in the stator 21. The rotor 22 rotates due to electrical interaction with the stator 21. In the embodiment shown, the upper portion of the shaft 40 is received into the center of the rotor 22 and rotates with the rotor 22. The lower portion of the shaft 40 is formed with an eccentric shaft 41 to be eccentrically rotated. In the embodiment shown, a longitudinal axis 40 a of the shaft 40 is not concentric with a longitudinal axis 41 a of the eccentric shaft 41. Thus when the shaft 40 rotates, the eccentric shaft 41 travels in a circular path around the longitudinal axis of the shaft 40.

The compression unit 10 includes a cylinder 11 formed with a compression chamber 11 a, a piston 12 installed to linearly reciprocate within the compression chamber 11 a, a cylinder head 13 coupled with a side of the cylinder 11 to seal the compression chamber 11 a, and a valve device 14 disposed between the cylinder 11 and the cylinder head 13. The piston 12 is connected to the eccentric shaft 41 by a connecting rod 15. The cylinder head 13 has a refrigerant suction chamber 13 a and a refrigerant discharge chamber 13 b partitioned from each other. The valve device 14 controls the flow of the refrigerant to be suctioned from the refrigerant suction chamber 13 a into the compression chamber 11 a or to be discharged from the compression chamber 11 a into the refrigerant discharge chamber 13 b.

Between the refrigerant suction chamber 13 a and the suction pipe 2, a suction muffler 50 is installed to reduce pressure ripples in the refrigerant entering the refrigerant suction chamber 13 a so as to reduce noise. The suction muffler 50 includes a main body 60 and a refrigerant guide pipe 70. The refrigerant guide pipe 70 is inserted into the refrigerant suction chamber 13 a of the cylinder head 13.

When the driving unit 20 causes the shaft 40 to rotate, the eccentric shaft 41 converts the rotation of the shaft 40 into a linearly reciprocating movement of the piston 12. Since the piston 12 is coupled to the eccentric shaft 41 by the connecting rod 15, when the eccentric shaft 41 eccentrically rotates, the piston 12 linearly reciprocates within the compression chamber 11 a. The linearly reciprocating motion of the piston 12 gives rise to a suction pressure alternating with a discharge pressure within the compression chamber 11 a.

As the eccentric shaft 41 rotates to cause the piston 12 to move away from the cylinder head 13, the suction pressure developed by the motion of the piston 12 causes the refrigerant from the evaporator to move through the suction pipe 2 to the main body 60 of the suction muffler 50. The refrigerant is diffused in the main body 60 and enters the refrigerant suction chamber 13 a through refrigerant guide pipe 70 with reduced pressure ripples. The refrigerant is then suctioned into the compression chamber 11 a from the refrigerant suction chamber 13 a through the valve device 14.

Then, as the eccentric shaft 41 rotates to cause the piston 12 to move towards the cylinder head 13, the refrigerant is compressed in the compression chamber 11 a. The piston 12 moving towards the cylinder head 13 also discharges the refrigerant from the compression chamber 11 a into the refrigerant discharge chamber 13 b through the valve device 14. The refrigerant is then transmitted by the discharge pipe 3 to a condenser outside the sealed casing 1.

When the hermetic type compressor initially starts or restarts after being stopped for a predetermined time, a high-pressure side of the refrigeration cycle reaches equilibrium with a low-pressure side of the refrigeration cycle. When the high-pressure side and low-pressure side are in equilibrium, an increased amount of the liquid refrigerant enters the hermetic type compressor. When an excessive quantity of the liquid refrigerant is suctioned into and compressed in the compression chamber 11 a together with the gaseous refrigerant, compression efficiency of the hermetic type compressor drops, and the refrigerating efficiency of the refrigeration cycle deteriorates. When a larger amount of the liquid refrigerant is transmitted into the suction muffler 50, the load applied to the compression unit 10 to suction the refrigerant liquid and the driving unit 20 to drive the compression unit increases. The increased load increases the noise of the hermetic type compressor and increases power loss.

Referring to FIG. 2, the suction muffler 50 is shown. To prevent significant suctioning of the liquid refrigerant into the compression chamber 11 a, the hermetic type compressor according to the present invention is provided with a pressure adjusting device 80 on a side of the main body 60 of the suction muffler 50 to keep internal pressure of the suction muffler 50 substantially constant.

The suction muffler includes the main body 60, an upper body 61, a lower body 62, a suction port 60 a, the refrigerant guide pipe 70, and the pressure adjusting device 80. The upper body 61 coupled with the lower body 62 to form the main body 60. The main body 60 has a suction port 60 a formed at a side thereof. The suction pipe 2 is coupled with the suction port 60 a by interposing a coil spring 4 therebetween (shown in FIGS. 4 and 5).

Referring to FIG. 3, the pressure adjusting device 80 is shown. The pressure adjusting device 80 includes an opening 81 preferably penetrating an upper side of the upper body 61, a step 81 a disposed on an edge of the opening 81, an opening and closing member 82 installed to open and close the opening 81, and an elastic member 83 to provide a force to move the opening and closing member 82 towards the opening 81.

Preferably, the opening and closing member 82 is formed substantially as a plate with a predetermined size and hinged to a side of the opening 81 to pivot to open and close the opening 81. The step 81 a supports the opening and closing member 82 when it closes the opening 81 and prevents the opening and closing member 82 from pivoting into the opening 81.

To hingedly couple the opening and closing member 82, penetrating holes 82 a are formed at an end of the opening and closing member 82. Corresponding penetrations 81 b are formed substantially adjacent to the opening 81 and align with the penetrating holes 82 a on the opening and closing member 82. The opening and closing member 82 pivots about a hinge shaft 84 received in the penetrating holes 82 a and the corresponding penetrations 81 b. The elastic member is disposed on the hinge shaft 84. In the embodiment shown, the elastic member 83 is a torsion spring.

To dispose the elastic member 83 on the hinge shaft 84, the opening and closing member 82 is formed with a cut-out part 82 b. The cutout part 82 b is disposed on an end of the opening and closing member 82 to correspond with an intermediate portion of the hinge shaft 84. The elastic member 83 is wound around the hinge shaft 84 where the hinge shaft 84 is exposed by the cut-out part 82 b. An end of the elastic member 83 is supported by an inner surface of the upper body 61, and an opposite end of the elastic member 83 is supported by an outer surface of the opening and closing member 82. Thus, the elastic member 83 elastically supports the opening and closing member 82 in a direction towards the opening 81. The step 81 a prevents the opening and closing member 82 from pivoting into the opening 81 when the opening and closing member 82 is closing the opening 81.

The weight of the opening and closing member 82 and the elasticity of the elastic member 83 are set such that the opening and closing member 82 opens when an excess quantity of the liquid refrigerant enters the suction muffler 50 and an internal pressure of the suction muffler 50 increases over a predetermined value. When the internal pressure of the suction muffler 50 is higher than the predetermined value, the opening and closing member 82 opens so that a substantial portion of the liquid refrigerant is discharged into the sealed casing 1 through the opening 81.

Thus, in the hermetic type compressor according to the present invention, the pressure adjusting device 80 prevents an excessive quantity of the liquid refrigerant from entering the compression chamber 11 a and being transmitted to the condenser of the refrigeration cycle. Therefore, the compression efficiency of the refrigerant and the refrigerating efficiency of the refrigeration cycle is substantially maintained.

Moreover, when the hermetic type compressor initially starts or restarts and an excessive quantity of the liquid refrigerant is transmitted into the suction muffler 50, the pressure adjusting device 80 discharges a majority of the refrigerant liquid into the sealed casing 1 through the opening 81 thereby preventing the internal pressure of the suction muffler 50 from increasing. Thus, the compression unit 10 and the driving unit 20 are not excessively overloaded. Therefore, the hermetic type compressor emits less noise and power loss does not increase.

FIGS. 4 and 5 illustrate the operation of the pressure adjusting device 80. Referring to FIG. 4, the suction muffler 50 is shown in cross-section with arrows to indicate the flow of the refrigerant. The refrigerant guide pipe 70 includes in inlet port 71 to receive the refrigerant and an outlet port 72 to discharge the refrigerant. The refrigerant guide pipe 70 extends into the main body 60 by a predetermined length. The suction muffler 50 is installed such that the outlet port 72 is inserted into the refrigerant suction chamber 13 a of the cylinder head 13.

The refrigerant enters the suction muffler 50 from the evaporator via the suction pipe 2, the coil spring 4, and the suction port 60 a. The refrigerant is subsequently diffused into the main body 60 to reduce the pressure ripples and is guided to the refrigerant guide pipe 70. Preferably, between the inner surface of the upper body 61 and the inlet port 71 of the refrigerant guide pipe 70, a small gap is provided to increase the flow rate of the refrigerant. The refrigerant enters the refrigerant guide pipe 70 through the inlet port 71 and then enters the refrigerant suction chamber 13 a through the outlet port 72.

The opening 81 is preferably formed at a position in the upper body 61 near where the inlet port 71 is formed and where the flow rate is increased so that the liquid refrigerant is more effectively discharged through the opening 81. Thus, when the internal pressure of the suction muffler 50 increases, the opening and closing member 82 pivots outward to open the opening 81. An angle between the opening 81 and the opening and closing member 82 increases in proportion to the internal pressure of the suction muffler 50.

Since a majority of the liquid refrigerant entering the main body 60 of the suction muffler 50 is discharged through the opening 81 into the sealed casing 1, the liquid refrigerant is substantially prevented from being suctioned into the compression chamber 11 a or being transmitted to the condenser of the refrigeration cycle. Thus, the load applied to the compression unit 10 and the driving unit 20 does not increase.

The liquid refrigerant discharged into the sealed casing 1 through the opening 81 when the hermetic type compressor starts or restarts evaporates and enters the suction muffler 50 through the coil spring 4. The liquid refrigerant evaporates when an internal temperature of the sealed casing 1 increases. The refrigerant that enters the suction muffler 50 through the coil spring 4 is guided to the refrigerant suction chamber 13 a together with the refrigerant from the suction pipe 2.

Referring to FIG. 5, after startup as the hermetic type compressor is continuously driven and the quantity of the liquid refrigerant decreases, the internal pressure falls below the predetermined value, and the opening and closing member 82 pivots towards the opening 81 due to the elastic force of the elastic member 83. When the opening 81 closed, all the refrigerant entering the main body 60 enters the refrigerant suction chamber 13 a through the refrigerant guide pipe 70 and is transmitted to the compressing chamber 11 a.

As described above, the hermetic type compressor according to the present invention includes a pressure adjusting device provided on a side of a suction muffler to maintain the internal pressure in the suction muffler substantially constant. When the hermetic type compressor initially starts or restarts, excessive liquid refrigerant enters the suction muffler and increases the internal pressure. The pressure adjusting device discharges a majority of the liquid refrigerant entering the suction muffler into the sealed casing thereby substantially maintaining the internal pressure of the suction muffler substantially constant. The hermetic type compressor of the present invention effectively prevents the liquid refrigerant from being suctioned into the compression chamber and transmitted to the condenser of the refrigeration cycle during initial start and restarts. Also, the hermetic type compressor of the present invention effectively prevents an increase in the load on the compression unit and the driving unit.

Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. 

1. A hermetic type compressor comprising: a sealed casing; a suction pipe penetrating a side of the sealed casing; a suction muffler disposed within the sealed casing and coupled to the suction pipe; a compression unit disposed within the sealed casing and coupled to the suction muffler; a driving unit disposed within the sealed casing and coupled to the compression unit; and a pressure adjusting device provided on the suction muffler maintaining internal pressure of the suction muffler substantially constant, the pressure adjusting device configured to discharge liquid refrigerant into the sealed casing.
 2. The hermetic type compressor according to claim 1, wherein the suction muffler further comprises: a main body including a suction port formed at a side thereof; and a refrigerant guide pipe including an end extended into the main body by a predetermined length to guide refrigerant guided into the main body to the compression unit.
 3. The hermetic type compressor according to claim 2, wherein the pressure adjusting device further comprises: an opening formed at a side of the main body; an opening and closing member installed substantially adjacent to the opening; and an elastic member biasing the opening and closing member to close the opening.
 4. The hermetic type compressor according to claim 2, wherein the opening and closing member is hinged to an end of the opening and pivots to open and close the opening.
 5. The hermetic type compressor according to claim 3, wherein the pressure adjusting device further comprises a hinge shaft penetrating an end of the opening and closing member and coupled with the main body of the suction muffler positioned at the opening.
 6. The hermetic type compressor according to claim 3, wherein the elastic member comprises a torsion spring wound around the hinge shaft and having an end supported by an inner side of the main body and an opposite end supported by an outer surface of the opening and closing member.
 7. The hermetic type compressor according to claim 3, wherein the opening is formed at a position near an end of the refrigerant guide pipe.
 8. The hermetic type compressor according to claim 3, wherein the opening further comprises a step to prevent the opening and closing member from being pivoted into the opening.
 9. A pressure adjusting device for a suction muffler of a compression unit comprising: an opening formed at a side of the suction muffler; an opening and closing member pivotably coupled to the side of the suction muffler substantially adjacent to the opening to open and close the opening; and an elastic member with one end coupled to the side of the suction muffler and another end coupled to the opening and closing member biasing the opening and closing member towards the opening; wherein the opening and closing member opens when an internal pressure of the suction muffler increases above a predetermined value.
 10. The pressure adjusting device according to claim 9, wherein the opening further comprises a step to prevent the opening and closing member from being pivoted into the opening.
 11. The pressure adjusting device according to claim 9, further comprising: a penetrating hole disposed substantially adjacent to the opening; a corresponding penetration disposed on the opening and closing member, the corresponding penetration aligning with the penetrating hole; and a hinge shaft disposed in the penetrating hole and the corresponding penetration.
 12. The pressure adjusting device according to claim 9, wherein the elastic member is a torsion spring with an end coupled to the side of the suction muffler and another end coupled to the opening and closing member.
 13. The pressure adjusting device according to claim 12, wherein the torsion spring is disposed on the hinge shaft.
 14. A pressure adjusting device for a suction muffler of a compression unit comprising: an opening formed at a side of the suction muffler; an opening and closing member pivotably coupled to the side of the suction muffler substantially adjacent to the opening to open and close the opening, the opening and closing member formed with a cut-out part; a penetrating hole disposed on the opening and closing member; a corresponding penetration disposed substantially adjacent to the opening, the corresponding penetration aligning with the penetrating hole; a hinge shaft disposed in the penetrating hole and the corresponding penetration; and a torsion spring disposed on the hinge shaft with an end coupled to the side of the suction muffler and another end coupled to the opening and closing member biasing the opening and closing member towards the opening; wherein the opening and closing member opens when an internal pressure of the suction muffler increases above a predetermined value.
 15. The pressure adjusting device according to claim 14, wherein the opening further comprises a step to prevent the opening and closing member from being pivoted into the opening. 